Silchar (Assam), Sep 27 : A number of NGOs and local parties Wednesday began an indefinite blockade of the national highway connecting Silchar of southern Assam with Mizoram to protest against alleged harassment of non-Mizos, leaving commuters stranded on either side.

The NH-306 (formerly NH 54) is the only surface communication link between land-locked Mizoram and the rest of India.

The road blockade was called by All Barak Youth Students' Association (ABYSA) in association with some local non-political parties, and a number of clubs and social organisations.

The agitators put up the blockade Wednesday morning at Lailapur near the Assam-Mizoram border, 450 km west of Assam's main city of Guwahati.

A huge number of vehicles and passengers were stranded on either side of the blockade.

ABYSA chief convener Baharul Islam Barbhuiya said: "Non-Mizo workers working in Mizoram are being harassed for quite some times in the name of Inner-Line Permit (ILP)."

"The persecutions are being carried out by Young Mizo Association (YMA) and some other Mizoram-based NGOs."

He told reporters: "As a result of the harassment, thousands of non-Mizo workers have fled from neighbouring Mizoram during the past few weeks."

The ILP, or the Bengal Eastern Frontier Regulation, has been in force in Mizoram, Nagaland and Arunachal Pradesh in the northeastern region since 1873.

Any non-domicile person has to obtain the ILP before entering these states.

Barbhuiya said the Mizoram government used to allow non-Mizo workers of the neighbouring states for different jobs in the tribal-dominated state on the basis of work permit issued by the authorities.

The work permits were issued for a period of 15 days and were renewable after the stipulated period.

"Recently the members of YMA and other organisations told the non-Mizo people that such work permit is not a valid document for them to enter any part of Mizoram and work there.

"Subsequently, the YMA cadres have started harassing non-Mizo workers on this pretext, while the government has remained silent," Barbhuiya said.

The ABYSA and its supporting organisations have urged Mizoram authorities to allow workers from outside to work there.

The NGOs have also threatened to intensify the economic blockade against Mizoram if the authorities did not take action against the harassment.

Ethnic tension in southern Assam and adjoining Mizoram deepened earlier this month following destruction of a border pillar by unidentified miscreants.

Several local organisations and NGOs of Cachar district, including ABYSA, have been organising rallies for the past few days to condemn the incident and demanded steps to immediately resolve the border dispute between the two states.

Mizoram, a mountainous state, has a 123-km border with Assam, 66 km with Tripura and 96 km with Manipur -- with which it has no dispute.

It also has an international border of 404 km with Myanmar and 318 km with Bangladesh.

The Meghalaya-Assam, Arunachal Pradesh-Assam and Mizoram-Assam boundary disputes occasionally create trouble between villagers, security forces and officials in these states.

The Mizoram government earlier this year had formed an official committee to resolve its boundary disputes with Assam.

Several organisations of Mizoram, including Zoram Nationalist Party (ZNP), have alleged that the Assam government recently unilaterally set up a border pillar in Mizoram territory "to grab" the state's land.